A number of resins which are cured or polymerized in response to light are known. Perhaps the most familiar of these are resins or composites used in dental technology. Dental composites are used to fill cavities, bond abraded enamel and for many cosmetic applications. When irradiated with light, dental resins polymerize due to a metacrylate based curing mechanism. Photo-initiators, such as camphor quinone and phosphine oxide, start the curing process by absorbing a broad band within the blue spectral range. For example, camphor quinone has an absorption maximum of about 472 namometers (nm), while phosphine oxide has an absorption maximum of 430 nm.
Light of this wavelength can be generated by tungsten-halogen lamps, laser diodes or light emitting diodes (U.S. Pat. No. 6,159,005). In order to achieve light of sufficient intensity for photopolymerization when using light emitting diodes (LEDs), it is often necessary to employ a plurality of LEDs (U.S. Pat. No. 5,420,768, U.S. Pat. No. 5,634,711 and U.S. Pat. No. 6,102,696). Photocuring devices which utilize a plurality of LEDs consume a great deal of power and produce much heat. This increased energy requirement contributes to the weight and complexity of these devices. Further, complicated systems are needed to capture and focus the light from the multiple LEDs which reduce the efficiency of current devices.
From the foregoing, it is apparent that a light-weight, cool-running and efficient hand-held photocuring device is needed. This device preferably is powered by a self-contained source, for example, a simple battery, so that the device is portable and not encumbered with cords. The device should be light-weight so that it is easily maneuvered during delicate procedures and should run cool so as not to adversely affect the polymerization process by providing excess heat to the photopolymerization reaction.
All patents, patent applications, provisional patent applications and publications refered to or cited herein, are incorporated by reference in their entirety to the extent they are not inconsistent with the explicit teachings of the specification